Method of restoring semiconductor device performance

Abstract

Contaminant metal residue on an organic passivation layer of a semiconductor device is removed by plasma etching thereof whereby the performance of the device is restored.

What we claim as our invention and desire to have secured by Letters Patent of the United States is: 
     
       1. A method of removing contaminant metal layers from an organic passivation layer of a semiconductor device, comprising wet chemical etching of said layers followed by plasma etching of metal residue of said contaminant metal layers with an etchant gas at sufficient electric field power and for a sufficient time to remove said metal residue. 
     
     
       2. The method of claim 1 wherein said organic passivation layer comprises a polymeric layer. 
     
     
       3. The method of claim 2 wherein said polymeric layer comprises a polyimide. 
     
     
       4. The method of claim 2 wherein said polymeric layer comprises a polyimide-siloxane copolymer. 
     
     
       5. The method of claim 1, 2,3 or 4 wherein said semiconductor device utilizes a voltage in excess of about 100 volts. 
     
     
       6. The method of claim 5 wherein said semiconductor device comprises one of the group consisting of a power Darlington transistor, a diode, a bipolar transistor, a MOSFET, and a silicon-controlled rectifier. 
     
     
       7. The method of claim 1, 2, 3 or 4 wherein said semiconductor device comprises a power Darlington transistor. 
     
     
       8. The method of claim 5 wherein said etchant gas comprises CF 4  and O 2  in about a ten-to-one ratio. 
     
     
       9. The method of claim 8 wherein said etching continues for a duration of about 4 minutes at an electric field power of about 300 watts. 
     
     
       10. The method of claim 7 wherein said contaminant metal layers comprises contaminant metal layers of a solder bumping process.